Cell signaling effected by tumor necrosis factor (TNF) is critical for a number for immune processes. The signal is triggered by binding of ligand to the TNF receptor at the cell surface and transmitted by molecules that bind the cytoplasmic portion of the TNF receptors. These binding proteins, called TRAFs, are novel proteins and their function is still being characterized. We have produced crystals of a TRAF molecule that diffract to high resolution and the crystals form in space group R32 with a=b=85 E, c=320 E. We plan to use MAD phasing to solve the structure.